By partnering with NSR, Terracastus will add extensive knowledge in landfill use and gain access to a major landfill in Helsingborg. The Acrion liquefaction process reduces the temperature of the biogas to approximately
-52 degrees Celsius (-67 Fahrenheit) upon which the carbon dioxide is converted into a liquid. The carbon dioxide is then used to “wash” the biogas upgrading it to 100 percent methane. As a last step the methane is turned into liquid by further reducing the temperature.
Terracastus has already tested the process in a pilot plant in the United States funded by the U.S. Energy Department. The new facility in Helsingborg is projected to be completed in fall 2011. Unlike the United States, there is no national biogas grid in Sweden which will make liquid biogas an attractive option. It will be easier to transport as compressed biogas requires about three times as much space. There is already a strong demand for biogas in Sweden, the new plant will produce approximately 15 million cubic meters of biogas a year – the Helsingborg city busses alone consume 4 million cubic meters annually.